Although the world’s first vaccine, for smallpox, was a wonderful invention, it would be an error to assume that smallpox would still be with us if the vaccine had not been invented. In fact, it would have disappeared sooner than it did because the remedy which finally eradicated it – isolation – had been known for hundreds of years but was neglected and never properly implemented before the Smallpox Eradication Program (SEP).
1. Isolation was invented in the 1350s: Isolation of the sick was applied to a number of diseases since around 1350 AD and while it was not capable of controlling the plague (which is spread by rats) it was eminently suited for smallpox. Many people must have observed over the years that smallpox doesn’t spread very rapidly and can therefore be controlled by isolation. By the 1670s, isolation for smallpox was well known. A 2011 paper by Elizabeth Tandy notes that isolation for smallpox was practiced in Salem in 1678. In 1731, an Act in Massachusetts required a smallpox-affected house to hang a pole bearing a red flag and take due precautions. In 1765, this practice was strengthened by appointing guards to stop any visitation to the affected house (appointing guards to stop visitors, by the way, is also precisely what the SEP did). In the UK, similar experience led to the first smallpox isolation hospital in 1746.
2. Haygarth’s pathbreaking scientific discovery of 1784: Dr John Haygarth of Chester studied smallpox in great detail in the 1770s. He found that it is not infectious beyond a short distance: “the air is rendered infectious, but to a little distance”. He proposed isolation as a remedy: “the Small-pox may be prevented, by keeping Persons, liable to the distemper, from approaching within the infectious distance of the variolous poison, till it can be destroyed”.
In 1778 Haygarth identified twenty families that had a smallpox case in their home and got them to abide by stringent Rules of Prevention: “I. Suffer no person, who has not had the small-pox to come into the infectious house. No visitor, who has any communication with persons liable to the distemper, should touch or sit down on anything infectious. II. No patient, after the pocks have appeared, must be suffered to go into the street, or other frequented place”. They would be rewarded with 10 shillings if they followed the rules. There was no requirement to vaccinate family members or contacts (the vaccine did not exist then, but even inoculation – the old method – was not required).
Haygarth then initiated extensive contact tracing to identify the sources of smallpox in each case and any further transmission in the town of Chester. Twelve of the twenty families strictly abided by the Rules and in their case no further spread of smallpox occurred. An independent inspector wrote in 1784: “I can certify that none of the remaining twelve families has communicated the distemper to a single person in Chester.” In addition to being a pioneer of contact tracing, Haygarth had proven beyond doubt that high quality isolation can break the chain of smallpox transmission.
Haygarth’s epidemiological findings have been validated. In a 2003 paper, Thomas Mack noted that smallpox “[t]ransmission would not be expected to occur over more than very short distances …. [the] virus is usually discharged not in droplet nuclei but in saliva droplets too large to be wafted long distances. Moreover, the viability of artificially airborne virus is measured in minutes”. Also, in a 1972 paper Mack noted that “the maximum excretion in severe cases [is] from six to nine days after onset, or about three to six days after rash appearance”. He explained in 2003 that “this period coincides with rapidly evolving symptoms severe enough to keep infectious patients in bed”. The smallpox patient becomes immobile when infectious. Overall, the “chain of transmission” of smallpox is therefore “inherently vulnerable”.
There are many learnings from Haygarth’s experiment. First, we don’t need vaccinations to eradicate smallpox. All that’s needed is that visitors (to be minimised) should be smallpox survivors (in the modern world, that too is not needed since N95 masks can easily block the extremely large sized smallpox virus). Second, isolation is best done in the patient’s own home. Third, isolation should be stringent.
In 1793, Haygarth recommended the creation of isolation hospitals for smallpox across England. It was a mistake since the idea of isolation hospitals doesn’t flow logically from his home-based experiment. In any case, after Jenner’s vaccine discovery in 1796, Haygarth’s work was neglected, with most doctors gravitating to the vaccine which generated riches for them.
3. James Simpson’s 1868 advocacy of isolation to eradicate smallpox: In an 1868 book, “Proposal to stamp out small-pox” Dr James Young Simpson strongly recommended isolation to eradicate smallpox. He wanted “The seclusion, at home or in hospital, of those affected, during the whole progress of the disease, as well as during the convalescence from it, or until all power of infecting others is past. The surrounding of the sick with nurses and attendants who are themselves non-conductors or incapable of being affected, inasmuch as they are known to be protected against the disease by having already passed through cow-pox or small-pox”.
In the meantime, the 1866 Sanitary Act had already authorised coercive isolation (at state expense) of smallpox patients in hospitals. John Simon, UK’s first chief medical officer, issued instructions in 1870 for isolation of smallpox patients across the UK. In 1879 Dr. Thomas Watson strongly supported James Simpson’s proposal, arguing that the one-time cost of eradication would be far less than the perennial cost of letting smallpox continue: “the continuance of these disorders among our people would unquestionably levy annually a far heavier pecuniary tax and loss, than many multiples of the one cost of their extinction”.
In the 1880s, a major experiment was launched in Leicester. Proposed in 1877 by Dr. William Johnston, smallpox patients were sent in Leicester to an isolation hospital and anyone who had potentially come in contact with the patient was quarantined at their home. The contacts could choose to take the vaccine but most didn’t. The results were outstanding and smallpox was well-controlled. This was further proof that isolation, not vaccination, is the best way to stop smallpox.
In the 1896 report of the British Royal Commission on Vaccination, a dissenting member, Dr William Collins advocated a strong focus on isolation: “[t]he evidence leads us irresistibly to the conclusion that the simplest and most successful method of limiting and stamping out small-pox outbreaks is and always has been to separate the diseased from the healthy, and to disinfect infected places, things, and persons”.
Despite all this, the medical profession still didn’t adopt a laser-focus on isolation. The practice, however, did become relatively commonplace by the end of the 19th century, mainly in isolation hospitals. Even this modest increase in isolation did wonders. While mass-scale vaccination had reduced smallpox since 1800, it had failed to eradicate the disease. After isolation became widespread, smallpox disappeared from most Western countries.
Disclaimer
Views expressed above are the author’s own.
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